Feat : Setup cloudflare worker for cloud endpoint

cloud/src/stubs/usageDb.js

@@ -0,0 +1,8 @@
+// Stub for cloud worker - no-op async functions
+export async function saveRequestUsage() {}
+export function trackPendingRequest() {}
+export async function appendRequestLog() {}
+export async function getUsageDb() { return { data: { history: [] } }; }
+export async function getUsageHistory() { return []; }
+export async function getUsageStats() { return {}; }
+export async function getRecentLogs() { return []; }